Bag filter apparatus and fabric filter bags used in such apparatus have been employed for some time for separating particulate material from fluids. One generally known use for such bag filter apparatus and fabric filter bags is in the field of handling grain and grain products such as flour and meal. Fabrics have been manufactured for specific use as fabric filter bags in such fields, in order that separation of solid particulate material from air, gas and the like may be accomplished. Persons familiar with the field of filtration generally will be aware of other uses for such fabrics, filter bags and filter bag apparatus.
Particularly in certain applications for such apparatus, bags and fabrics, a significant risk is presented by the accumulation or build-up of electrostatic charges in the filtering process. Certain fluids and/or particulate substances to be removed from the fluids are or can become explosive. For example, wheat flour being separated from air streams can, under proper circumstances, become explosive. Further, friction involved in such filtration frequently gives rise to electrostatic charges which occur or appear on components of a filter apparatus. Where an explosive or potentially explosive material is being filtered in an apparatus and through the use of bags and fabrics which accumulate electrostatic charges, explosions are possible which are capable of doing severe damage to the apparatus involved and, in certain circumstances, killing persons employed in the area of the filter apparatus.